In industry it is frequently necessary to cut a large-format rectangular plate up into a plurality of small rectangular plates. This is done, for instance, to make a plurality of printed-circuit boards from a large phenolic-resin laminate plate. An essential requirement of such systems is that the small plates be perfectly rectangular and have side dimensions which correspond exactly to the required sizes.
This procedure is normally done by means of separate shears. The starting workpiece is a large rectangular plate which is advanced stepwise in a main transport direction through a shear. With each step the shear cuts a strip off the end of the plate, it being a relatively easy job to ensure that these strips are all of identical length measured in the main transport direction.
Immediately downstream of this shear is a support arrangement which has a plurality of support feet which can be pneumatically moved upward and downward between parallel conveyor belts extending in the transport direction. They support the downstream end portion of the plate prior to and during cutting, so as principally to prevent the plate from bowing up underneath the blade of the shear. After shearing-off of the downstream end portions these support feet drop down to deposit the sheared-off end portions on a continuously driven conveyor belts which displace them downstream away from the shear. The conveyor belts can drop the sheared-off end portions on another conveyor or simply push them all up against an alignment bar.
The standard procedure is then to take the sheared-off end portions and manually advance them through yet another shear so as to cut them into pieces of the desired size. It has been suggested to then fit them manually into yet another apparatus which automatically shears them into the desired size, but this procedure has been found virtually as time-consuming as the manual shearing operation.
The obvious disadvantage of the above-described method and apparatus is that production costs are relatively high due to carrying out many of the steps manually. Furthermore the manual operation slows the entire procedure down greatly so that production speed is limited. Finally even if the slow speed and high labor costs could be tolerated, the finished product is normally not exactly to the desired dimensions, so that further monitoring steps are necessary to separate out the inaccurately cut sections.